Many electro-optic devices, such as flat panel displays, employ liquid crystal cells. Generally, liquid crystal cells include a liquid crystal medium between two polymer surfaces. Liquid crystals are organic compounds that are in an intermediate or mesomorphic state between solid and liquid phases. They are also birefringent as a consequence of a tendency of constituent liquid crystal molecules to align.
Typically, the polymer surfaces of liquid crystal cells are formed by unidirectionally rubbing a suitable polymer, such as a polyimide thin film coating, with a velvet cloth. Rubbing of the polymer causes orientation of the functional groups and formation of the parallel grooves. Orientation of the functional groups and formation of grooves in this manner causes alignment of liquid crystal molecules and a consequent uniform appearance of the liquid crystal medium. Application of an external motive force, such as an electric field, can then cause at least a portion of the liquid crystal to realign, thereby changing the appearance of that portion of the medium.
However, formation of liquid crystal cells by rubbing the polymer surfaces has several disadvantages. For example, rubbing often generates dust and causes accumulation of static charge. Both of these problems can, in turn, cause the formation of defects in the liquid crystal cell, or even failure of the electro-optical device incorporating a defective liquid crystal cell.
Therefore, a need exists for a method of liquid crystal alignment and for a method of fabricating liquid crystal cells that overcome or minimize the above-referenced problems.